Manufacture of α-olefins

ABSTRACT

Alpha-olefins are manufactured in high yield and with very high selectivity by contacting ethylene with an iron complex of a selected 2,6-pyridinedicarboxaldehyde bisimine or a selected 2,6-diacylpyridine bisimine, and in some cases a selected activator compound such as an alkyl aluminum compound. Novel bisimines and their iron complexes are also disclosed. The α-olefins are useful as monomers and chemical intermediates.

This application claims the benefit of U.S. Provisional Application Ser.No. 60/052,604, filed Jul. 15, 1997 and of U.S. Provisional ApplicationSer. No. 60/065,538, filed Nov. 14, 1997.

FIELD OF THE INVENTION

Alpha-olefins may be manufactured in high yield and with very highselectivity by contacting ethylene with an iron complex of a selected2,6-pyridinedicarboxaldehyde bisimine or a selected 2,6-diacylpyridinebisimine, and usually a selected activator compound.

TECHNICAL BACKGROUND

Alpha-olefins, especially those containing about 6 to about 20 carbonatoms, are important items of commerce, with about 1.5 million tonsreportedly being produced in 1992. The α-olefins are used asintermediates in the manufacture of detergents, as monomers (especiallyin linear low density polyethylene), and as intermediates for many othertypes of products. As a consequence, improved methods of making thesecompounds are of interest.

Most commercially produced α-olefins are made by the oligomerization ofethylene, catalyzed by various types of compounds, see for instance B.Elvers, et al., Ed. Ullmann's Encyclopedia of Industrial Chemistry, Vol.A13, VCH Verlagsgesellschaft mbH, Weinheim, 1989, p. 243-247 and275-276, and B. Cornils, et al., Ed., Applied Homogeneous Catalysis withOrganometallic Compounds, A Comprehensive Handbook, Vol. 1, VCHVerlagsgesellschaft mbH, Weinheim, 1996, p. 245-258. The major types ofcommercially used catalysts are alkylaluminum compounds, certainnickel-phosphine complexes, and a titanium halide with a Lewis acid suchas AlCl₃. In all of these processes significant amounts of branchedand/or internal olefins and/or diolefins, are produced. Since in mostinstances these are undesired, and often difficult to separate from thedesired linear α-olefins, minimization of these byproducts is sought.

SUMMARY OF THE INVENTION

This invention concerns a first process for the production of α-olefins,comprising, contacting, at a temperature of about -100° C. to about+300° C., a compound of the formula ##STR1## with ethylene and: (a) afirst compound W, which is a neutral Lewis acid capable of abstractingX⁻ an alkyl group or a hydride group from Fe to form WX⁻, (WR²⁰)⁻ or WH⁻and which is also capable of transferring an alkyl group or a hydride toFe, provided that WX⁻ is a weakly coordinating anion; or

(b) a combination of second compound which is capable of transferring analkyl or hydride group to Fe and a third compound which is a neutralLewis acid which is capable of abstracting X⁻, a hydride or an alkylgroup from Fe to form a weakly coordinating anion;

wherein:

each X is an anion;

n is 1, 2 or 3 so that the total number of negative charges on saidanion or anions is equal to the oxidation state of an Fe atom present in(I);

R¹, R² and R³ are each independently hydrogen, hydrocarbyl, substitutedhydrocarbyl, or an inert functional group;

R⁴ and R⁵ are each independently hydrogen, hydrocarbyl, an inertfunctional group or substituted hydrocarbyl;

R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are each independently hydrogen,hydrocarbyl, an inert functional group or substituted hydrocarbyl;

R⁸ is a primary carbon group, a secondary carbon group or a tertiarycarbon group; and

R²⁰ is alkyl;

and provided that:

when R⁸ is a primary carbon group none, one or two of R¹², R¹³ and R¹⁷are primary carbon groups, and the remainder of R¹², R¹³ and R¹⁷ arehydrogen;

when R⁸ is a secondary carbon group, none or one of R¹², R¹³ and R¹⁷ isa primary carbon group or a secondary carbon group and the remainder ofR¹², R¹³, and R¹⁷ are hydrogen;

when R⁸ is a tertiary carbon group all of R¹², R¹³ and R¹⁴ are hydrogen;and

any two of R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶ and R¹⁷ vicinal toone another, taken together may form a ring.

Also disclosed herein is a compound of the formula ##STR2## wherein:each X is an anion;

n is 1, 2 or 3 so that the total number of negative charges on saidanion or anions is equal to the oxidation sate of a Fe atom present in(I);

R¹, R² and R³ are each independently hydrogen, hydrocarbyl, substitutedhydrocarbyl, or an inert functional group;

R⁴ and R⁵ are each independently hydrogen, hydrocarbyl, an inertfunctional group or substituted hydrocarbyl; and

R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are each independently hydrogen,hydrocarbyl, an inert functional group or substituted hydrocarbyl; R⁸ isa primary carbon group, a secondary carbon group or a tertiary carbongroup;

and provided that:

when R⁸ is a primary carbon group none, one or two of R¹², R¹³ and R¹⁷are primary carbon groups, and the remainder of R¹², R¹³ and R¹⁷ arehydrogen;

when R⁸ is a secondary carbon group, none or one of R¹², R¹³ and R¹⁷ isa primary carbon group or a secondary carbon group and the remainder ofR¹², R¹³, and R¹⁷ are hydrogen; and

when R⁸ is a tertiary carbon group all of R¹², R¹³ and R¹⁴ are hydrogen;any two of R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶ and R⁷¹ vicinal toone another, taken together may form a ring.

This invention includes a compound of the formula ##STR3## wherein: R¹,R² and R³ are each independently hydrogen, hydrocarbyl, substitutedhydrocarbyl, or an inert functional group;

R⁴ and R⁵ are each independently hydrogen, hydrocarbyl, an inertfunctional group or substituted hydrocarbyl; and

R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are each independently hydrogen,hydrocarbyl, an inert functional group or substituted hydrocarbyl; R⁸ isa primary carbon group, a secondary carbon group or a tertiary carbongroup;

and provided that:

when R⁸ is a primary carbon group none, one or two of R¹², R¹³ and R¹⁷are primary carbon groups, and the remainder of R¹², R¹³ and R¹⁷ arehydrogen;

when R⁸ is a secondary carbon group, none or one of R¹², R¹³ and R¹⁷ isa primary carbon group or a secondary carbon group and the remainder ofR¹², R¹³, and R¹⁷ are hydrogen;

when R⁸ is a tertiary carbon group all of R¹², R¹³ and R¹⁴ are hydrogen;and

any two of R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶ and R¹⁷ vicinal toone another, taken together may form a ring.

This invention also concerns a second process for the production ofα-olefins, comprising contacting, at a temperature of about -100° C. toabout +300° C., a Fe[II] or Fe[III] complex of a tridentate ligand ofthe formula ##STR4## with ethylene, wherein: R¹, R² and R³ are eachindependently hydrogen, hydrocarbyl, substituted hydrocarbyl, or aninert functional group;

R⁴ and R⁵ are each independently hydrogen, hydrocarbyl, an inertfunctional group or substituted hydrocarbyl;

R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are each independently hydrogen,hydrocarbyl, an inert functional group or substituted hydrocarbyl;

R⁸ is a primary carbon group, a secondary carbon group or a tertiarycarbon group;

and provided that:

when R⁸ is a primary carbon group none, one or two of R¹², R¹³ and R¹⁷are primary carbon groups, and the remainder of R¹², R¹³ and R¹⁷ arehydrogen;

when R⁸ is a secondary carbon group, none or one of R¹², R¹³ and R¹⁴ isa primary carbon group or a secondary carbon group and the remainder ofR¹², R¹³, and R¹⁷ are hydrogen;

when R⁸ is a tertiary carbon group all of R¹², R¹³ and R¹⁴ are hydrogen;

any two of R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶ and R¹⁷ vicinal toone another, taken together may form a ring;

an Fe[II] or Fe[III] atom also has bonded to it an empty coordinationsite or a ligand that may be displaced by said ethylene, and a ligandthat may add to said ethylene.

This invention also includes a compound of the formula ##STR5## wherein:R¹, R² and R³ are each independently hydrogen, hydrocarbyl, substitutedhydrocarbyl, or an inert functional group;

R⁴ and R⁵ are each independently hydrogen, hydrocarbyl, an inertfunctional group or substituted hydrocarbyl,

R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are each independently hydrogen,hydrocarbyl, an inert functional group or substituted hydrocarbyl;

R⁸ is a primary carbon group, a secondary carbon group or a tertiarycarbon group;

T¹ is hydride or alkyl or any other anionic ligand into which ethylenecan insert;

Y is a vacant coordination site, or neutral ligand capable of beingdisplaced by ethylene;

Q is a relatively non-coordinating anion; and

P is a divalent (poly)ethylene group of the formula --(CH₂ CH₂)_(x) --wherein x is an integer of 1 or more;

and provided that:

when R⁸ is a primary carbon group none, one or two of R¹², R¹³ and R¹⁷are primary carbon groups, and the remainder of R¹², R¹³ and R¹⁷ arehydrogen;

when R⁸ is a secondary carbon group, none or one of R¹², R¹³ and R¹⁷ isa primary carbon group or a secondary carbon group and the remainder ofR¹², R¹³, and R¹⁷ are hydrogen;

when R⁸ is a tertiary carbon group all of R¹², R¹³ and R¹⁴ are hydrogen;and

any two of R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶ and R¹⁷ vicinal toone another, taken together may form a ring.

This invention also concerns a third process for the production ofα-olefins, comprising, contacting, at a temperature of about -100° C. toabout +300° C., ethylene and a compound of the formula ##STR6## wherein:R¹, R² and R³ are each independently hydrogen, hydrocarbyl, substitutedhydrocarbyl, or an inert functional group;

R⁴ and R⁵ are each independently hydrogen, hydrocarbyl, an inertfunctional group or substituted hydrocarbyl,

R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are each independently hydrogen,hydrocarbyl, an inert functional group or substituted hydrocarbyl;

R⁸ is a primary carbon group, a secondary carbon group or a tertiarycarbon group;

T¹ is hydride or alkyl or any other anionic ligand into which ethylenecan insert;

Y is a vacant coordination site, or a neutral ligand capable of beingdisplaced by ethylene;

Q is a relatively non-coordinating anion; and

P is a divalent (poly)ethylene group of the formula --(CH₂ CH₂)_(x) --wherein x is an integer of 1 or more;

and provided that:

when R⁸ is a primary carbon group none, one or two of R¹², R¹³ and R¹⁷are primary carbon groups, and the remainder of R¹², R¹³ and R¹⁷ arehydrogen;

when R⁸ is a secondary carbon group, none or one of R¹², R¹³ and R¹⁷ isa primary carbon group or a secondary carbon group and the remainder ofR¹², R¹³, and R¹⁷ are hydrogen;

when R⁸ is a tertiary carbon group all of R¹², R¹³ and R¹⁴ are hydrogen;and

any two of R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶ and R¹⁷ vicinal toone another, taken together may form a ring.

DETAILS OF THE INVENTION

Herein, certain terms are used. Some of them are:

A "hydrocarbyl group" is a univalent group containing only carbon andhydrogen. If not otherwise stated, it is preferred that hydrocarbylgroups herein contain 1 to about 30 carbon atoms.

By "substituted hydrocarbyl" herein is meant a hydrocarbyl group whichcontains one or more substituent groups which are inert under theprocess conditions to which the compound containing these groups issubjected. The substituent groups also do not substantially interferewith the process. If not otherwise stated, it is preferred thatsubstituted hydrocarbyl groups herein contain 1 to about 30 carbonatoms. Included in the meaning of "substituted" are heteroaromaticrings.

By "(inert) functional group" herein is meant a group other thanhydrocarbyl or substituted hydrocarbyl which is inert under the processconditions to which the compound containing the group is subjected. Thefunctional groups also do not substantially interfere with any processdescribed herein that the compound in which they are present may takepart in. Examples of functional groups include halo (fluoro, chloro,bromo and iodo), ether such as --OR¹⁸ wherein R¹⁸ is hydrocarbyl orsubstituted hydrocarbyl. In cases in which the functional group may benear an iron atom, such as R⁴, R⁵, R⁸, R¹², R¹³, and R¹⁷ the functionalgroup should not coordinate to the iron atom more strongly than thegroups in compounds containing R⁴, R⁵, R⁸, R¹², R¹³ and R¹⁷ which areshown as coordinating to the iron atom, that is they should not displacethe desired coordinating group.

By an "alkyl aluminum compound" is meant a compound in which at leastone alkyl group is bound to an aluminum atom. Other groups such asalkoxide, oxygen, and halogen may also be bound to aluminum atoms in thecompound. See below for preferred alkylaluminum compounds.

By "neutral Lewis base" is meant a compound, which is not an ion, whichcan act as a Lewis base. Examples of such compounds include ethers,amines, sulfides, and organic nitrites.

By "cationic Lewis acid" is meant a cation which can act as a Lewisacid. Examples of such cations are sodium and silver cations.

By relatively noncoordinating (or weakly coordinating) anions are meantthose anions as are generally referred to in the art in this manner, andthe coordinating ability of such anions is known and has been discussedin the literature, see for instance W. Beck., et al., Chem. Rev., vol.88 p. 1405-1421 (1988), and S. H. Strauss, Chem. Rev., vol. 93, p.927-942 (1993), both of which are hereby included by reference. Amongsuch anions are those formed from alkylaluminum compounds, definedabove, and X⁻, including R⁹ ₃ AlX⁻, R⁹ ₂ AlClX⁻, R⁹ AlCl₂ X⁻, and "R⁹AlOX⁻ ". Other useful noncoordinating anions include BAF⁻{BAF=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate}, SbF₆ ⁻, PF₆ ⁻, andBF₄ ⁻, trifluoromethanesulfonate, p-toluenesulfonate, (R_(f) SO₂)₂ N⁻(wherein R_(f) is perfluoroalkyl), and (C₆ F₅)₄ B⁻.

By formation of an α-olefin is meant formation of a compound (or mixtureof compounds) of the formula H(CH₂ CH₂)_(q) CH=CH₂ wherein q is aninteger of 1 to about 18. In most such reactions, a mixture of compoundswill result which have differing values of q, and in most reactions toform the α-olefins some of the α-olefins formed will have q values ofmore than 18. Preferably less than 50 weight percent, more preferablyless than 20 weight percent of the product mixture will have q valuesover 18. The product mixture may contain small amounts (preferably lessthan 30 weight percent, more preferably less than 10 weight percent, andespecially preferably less than 2 weight percent) of other types ofcompounds such as alkanes, branched alkenes, dienes, and/or internalolefins.

By an empty coordination site is meant a potential coordination sitethat does not have a ligand bound to it. Thus if an ethylene molecule isin the proximity of the empty coordination site, the ethylene moleculemay coordinate to the metal atom.

By a "primary carbon group" herein is meant a group of the formula --CH₂--, wherein the free valence--is to any other atom (the bond representedby the hyphen is to the benzene ring to which the primary carbon groupis attached). Thus the free valence--may be bonded to a hydrogen atom,halogen atom, a carbon atom, an oxygen atom, a sulfur atom, etc. Inother words, the free valence--may be to hydrogen, hydrocarbyl,substituted hydrocarbyl or a functional group. Examples of primarycarbon groups include --CH₃, --CH₂ CH(CH₃)₂, --CH₂ Cl, --CH₂ C₆ H₅,--OCH₃ and --CH₂ OCH₃.

By a secondary carbon group is meant the group ##STR7## wherein bothfree bonds represented by the dashed lines are to an atom or atoms otherthan hydrogen. These atoms or groups may be the same or different. Inother words the free valences represented by the dashed lines may behydrocarbyl, substituted hydrocarbyl or functional groups. Examples ofsecondary carbon groups include --CH(CH₃)₂, --CHCl₂, --CH(C₆ H₅)₂,cyclohexyl, --CH(CH₃)OCH₃, and --CH═CCH₃.

By a "tertiary carbon group" is meant a group of the formula ##STR8##wherein the solid line is the bond to the benzene ring and the threefree bonds represented by the dashed lines are to an atom or atoms otherthan hydrogen. In other words, the bonds represented by the dashed linesare to hydrocarbyl, substituted hydrocarbyl or inert functional groups.Examples of tetiary carbon groups include --C(CH₃)₃, --C(C₆ H₅)₃,--CCl₃, --C(CH₃)₂ OCH₃, --C.tbd.CH, --C(CH₃)CH═CH₂, and 1-adamantyl.

By a ligand that may add to ethylene is meant a ligand coordinated to ametal atom into which an ethylene molecule (or a coordinated ethylenemolecule) may insert to start or continue an oligomerization. Forinstance, this may take the form of the reaction (wherein L is aligand): ##STR9## Note the similarity of the structure on the left-handside of this equation to compounds (V) and (VI) (see below).

Compounds useful as ligands are diimines of 2,6-pyridinedicarboxaldehydeor 2,6-diacylpyridines of the general formula ##STR10## wherein all ofthe "R" groups are as defined above. In preferred compounds (I) and(II), and all other preferred compounds in which the following "R"groups appear:

R⁴ and R⁵ are methyl or hydrogen; and/or

R¹, R², and R³ are all hydrogen; and/or

R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen; and/or

R¹² and R¹⁷ are each independently methyl, ethyl, propyl or isopropyl,more preferably both are methyl or ethyl; and/or

each X is a monovalent anion, more preferably selected from the groupconsisting of halide and nitrile.

It is also preferred that in all compounds in which they appear:

if R⁸ is a primary carbon group, R¹³ is a primary carbon group and R¹²and R¹⁷ are hydrogen;

if R⁸ is a secondary carbon group, R¹³ is a primary or secondary carbongroup, more preferably a secondary carbon group, and R¹² and R¹⁷ arehydrogen.

In all specific preferred compounds in which they appear it is preferredthat:

R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen,and R¹² and R¹⁷ are both methyl;

R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen,and R¹² and R¹⁷ are both ethyl;

R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen, andR¹² and R¹⁷ are both isopropyl;

R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen,and R¹² and R¹⁷ are both n-propyl;

R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen,and R¹² and 17are both chloro; and

R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen,and R¹² and R¹⁷ are both trifluoromethyl.

In all of the above specific compounds it is preferred that X isselected from the group consisting of chloride, bromide and nitrate, andmore preferably that it is chloride.

Compounds such as (II) and may be made by the reaction of a compound ofthe formula ##STR11## with a compound of the formula H₂ NR⁶ or H₂ NR⁷,wherein R⁶ and R⁷ are as described above. These reactions are oftencatalyzed by carboxylic acids, such as formic acid. Reactions such asthese are described in Examples 1-3.

The iron complexes may be formed by reacting the appropriate tridentateligand with an iron salt such as an iron halide or a compound such asiron [III] nitrate. See Examples 4-6 for preparation of iron complexes.

In the first oligomerization process (to produce α-olefins) describedherein an iron complex (I) is contacted with ethylene and a neutralLewis acid W capable of abstracting X⁻, hydride or alkyl (R²⁰) from (I)to form a weakly coordinating anion, and must alkylate or be capable ofadding a hydride ion to the iron atom, or an additional alkylating agentor an agent capable of adding a hydride anion to the iron atom must bepresent. The neutral Lewis acid is originally uncharged (i.e., notionic). Suitable neutral Lewis acids include SbF₅, Ar₃ B (wherein Ar isaryl), and BF₃. Suitable cationic Lewis acids or Bronsted acids includeNaBAF, silver trifluoromethanesulfonate, HBF₄, or [C₆ H₅ NH(CH₃)₂ ]⁺[B(C₆ F₅)₄ ]⁻. In those instances in which (I) (and similar catalystswhich require the presence of a neutral Lewis acid or a cationic Lewisor Bronsted acid), does not contain an alkyl or hydride group alreadybonded to the iron atom, the neutral Lewis acid or a cationic Lewis orBronsted acid also alkylates or adds a hydride to the iron or a separatealkylating or hydriding agent is present, i.e., causes an alkyl group(R²⁰) or hydride to become bonded to the iron atom.

It is preferred that R²⁰ contains 1 to 4 carbon atoms, and morepreferred that R²⁰ is methyl or ethyl.

For instance, alkyl aluminum compounds (see next paragraph) may alkylate(I). However, not all alkylaluminum compounds may be strong enough Lewisacids to abstract X⁻ or an alkyl group from the iron atom. In that casea separate Lewis acid strong enough to do the abstraction must bepresent. For instance, (C₆ F₅)₃ B or (C₆ H₅)₃ B are useful Lewis acids,and could be used in combination with, for example, an alkylaluminumcompound such as triethylaluminum.

A preferred neutral Lewis acid, which can alkylate the iron, is aselected alkyl aluminum compound, such as R¹⁹ ₃ Al, R¹⁹ AlCl₂, R¹⁹ ₂AlCl₂, and "R¹⁹ AlO" (alkylaluminoxanes), wherein R¹⁹ is alkylcontaining 1 to 25 carbon atoms, preferably 1 to 4 carbon atoms.Suitable alkyl aluminum compounds include methylaluminoxanes (which areoligomers with the general formula [MeAlO]_(n)), (C₂ H₅)₂ AlCl, C₂ H₅AlCl₂, and [(CH₃)₂ CHCH₂ ]₃ Al.

Metal hydrides such as NaBH₄ may be used to bond hydride groups to theFe.

In the second oligomerization process described herein an iron complexof (II) is either added to the oligomerization process or formed in situin the process. In fact, more than one such complex may be formed duringthe course of the process, for instance formation of an initial complexand then reaction of that complex to form an active ended oligomercontaining such a complex.

Examples of such complexes which may be formed initially in situ include##STR12## and wherein the "R" substituents are as defined above, T¹ ishydride or alkyl or any other anionic ligand into which ethylene caninsert, Y is a vacant coordination site, or a neutral ligand capable ofbeing displaced by ethylene, and Q is a relatively non-coordinatinganion. Complexes may be added directly to the process or formed in situ.For instance, (IV) may be formed by the reaction of (I) with a neutralLewis acid such as an alkyl aluminum compound. Another method of formingsuch a complex in situ is combining a suitable iron compound such ironchloride, (II) and an alkyl aluminum compound. Other iron salts in whichanions similar to chloride are present, and which may be removed byreaction with the Lewis or Bronsted acid. For instance iron halides,nitrates and carboxylates (such as acetates) may be used, particularlyif they are slightly soluble in the process medium. It is preferred thatthese precursor iron salts be at least somewhat soluble in the processmedium.

After the ethylene oligomerization has started, the complex may be in aform such as ##STR13## wherein, as before, the "R" substituents and Qare as defined above, and P is a divalent (oligo)ethylene group of theformula --(CH₂ CH₂)_(x) -- wherein x is an integer of 1 or more. The"end group" on P in this instance is written as H, since as theoligomerization proceeds to form α-olefins, the end group must ofnecessity be H. It could at some time, especially at the beginning ofthe oligomerization, be T¹. It is preferred that Fe be in +2 oxidationstate in (I), (IV), (V) and (VI).

Compounds such as (IV), (V) and (VI) may or may not be stable away froman environment similar to that of the oligomerization process.

(IV), (V) and (VI) may also be used, in the absence of any"co-catalysts" or "activators" to oligomerize ethylene in a thirdoligomerization process. Except for the ingredients in the process, theprocess conditions for the third process, such as temperature, pressure,oligomerization medium, etc., may be the same as for the first andsecond oligomerization processes, and preferred conditions for thoseprocesses are also preferred for the third oligomerization process.

In all the oligomerization processes herein, the temperature at which itis carried out is about -100° C. to about +300° C., preferably about 0°C. to about 200° C., more preferably about 50° C. to about 150° C. It ispreferred to carry out the oligomerization under ethylene (gauge)pressures from about 0 kPa to about 35 MPa, more preferably about 500kPa to about 15 MPa. It is preferred that the oligomerization be carriedunder conditions at which the reaction is not significantly diffusionlimited.

The oligomerization processes herein may be run in the presence ofvarious liquids, particularly aprotic organic liquids. The catalystsystem, ethylene, and α-olefin product may be soluble or insoluble inthese liquids, but obviously these liquids should not prevent theoligomerization from occurring. Suitable liquids include alkanes,alkenes cycloalkanes, selected halogenated hydrocarbons, and aromatichydrocarbons. Specific useful solvents include hexane, toluene, theα-olefins themselves, and benzene.

The formation of the α-olefins as described herein is relatively rapidin many instances, and significant yields can be obtained in less thanan hour. Under the correct conditions very high selectivity for anα-olefin is shown, see for instance Examples 8-17.

Also under the correct conditions mixtures of α-olefins containingdesirable numbers of carbon atoms are obtained. A measure of themolecular weights of the olefins obtained is factor K from theSchulz-Flory theory (see for instance B. Elvers, et al., Ed. Ullmann'sEncyclopedia of Industrial Chemistry, Vol. A13, VCH VerlagsgesellschaftmbH, Weinheim, 1989, p. 243-247 and 275-276. This is defined as:

    K=n(C.sub.n+2 olefin)/n(C.sub.n olefin)

wherein n(C_(n) olefin) is the number of moles of olefin containing ncarbon atoms, and n(C_(n+2) olefin) is the number of moles of olefincontaining n+2 carbon atoms, or in other words the next higher oligomerof C_(n) olefin. From this can be determined the weight (mass) fractionsof the various olefins in the resulting oligomeric reaction productmixture. The K factor is preferred to be in the range of about 0.7 toabout 0.8 to make the α-olefins of the most commercial interest. It isalso important to be able to vary this factor, so as to produce thoseolefins which are in demand at the moment. Examples 8 to 17 show thatthis can be done in the present oligomerization processes.

The α-olefins made herein may be further polymerized with other olefinsto form polyolefins, especially linear low density polyethylenes, whichare copolymers containing ethylene. They may also be homopolymerized.These polymers may be made by a number of known methods, such asZiegler-Natta-type polymerization, metallocene catalyzed polymerization,and other methods, see for instance World Patent Application 96/23010,see for instance Angew. Chem., Int. Ed. Engl., vol. 34, p. 1143-1170(1995), European Patent Application 416,815 and U.S. Pat. No. 5,198,401for information about metallocene-type catalysts, and J. Boor Jr.,Ziegler-Natta Catalysts and Polymerizations, Academic Press, New York,1979 and G. Allen, et al., Ed., Comprehensive Polymer Science, Vol. 4,Pergamon Press, Oxford, 1989, p. 1-108, 409-412 and 533-584, forinformation about Ziegler-Natta-type catalysts, and H. Mark, et al.,Ed., Encyclopedia of Polymer Science and Engineering, Vol. 6, John Wiley& Sons, New York, 1992, p. 383-522, for information about polyethylenes,and all of these are hereby included by reference.

The α-olefins made herein may be converted to alcohols by knownprocesses, these alcohols being useful for a variety of applicationssuch as intermediates for detergents or plasticizers. The α-olefins maybe converted to alcohols by a variety of processes, such as the oxoprocess followed by hydrogenation, or by a modified single step oxoprocess (the `modified Shell process`), see for instance B. Elvers, etal., Ed., Ullmann's Encyclopedia of Chemical Technology, 5^(th) Ed.,Vol. A18, VCH Verlagsgesellschaft mbH, Weinheim, 1991, p. 321-327, whichis hereby included by reference.

The ethylene oligomerizations herein may also initially be carried outin the solid state by, for instance, supporting and active catalyst orcatalyst precursor on a substrate such as silica or alumina. If acatalyst precursor, such as an iron halide or nitrate, it may beactivated with a Lewis (such as W, for instance an alkylaluminumcompound) and exposing it to ethylene. Alternatively a solution of thecatalyst precursor may be exposed to a support having an alkylaluminumcompound on its surface. The support may also be able to take the placeof the Lewis or Bronsted acid, for instance an acidic clay such asmontmorillonite. Another method of making a supported catalyst is tostart a polymerization or at least make an iron complex of anotherolefin or oligomer of an olefin such as cyclopentene on a support suchas silica or alumina. All of these "heterogeneous" catalysts may be usedto catalyze oligomerization in the gas phase or the liquid phase. By gasphase is meant that the ethylene is transported to contact with thecatalyst particle while the ethylene is in the gas phase.

Some of the compounds made or used in the Examples are shown below:##STR14##

EXAMPLE 1 Preparation of 2,6-bis-[1-(2-methylphenylimino)ethyl]pyridine,(VII)

One g of 2,6-diacetylpyridine and 3.0 ml of o-toluidine were added to anErlenmeyer flask with 20 ml of methylene chloride. A stirbar and 5 dropsof 97% formic acid were added, and the flask was sealed and the solutionwas stirred for 40 hours. The solvent was then removed in vacuo, and theflask was placed in the freezer at -30° C. The resulting viscous oil waswashed with cold methanol, and a yellow solid formed and was isolated byfiltration and identified by ¹ H NMR as the desired product (959 mg,45.9%). ¹ H NMR (CDCl₃): δ 8.38(d, 2, H_(pyr)), 7.86(t, 1, H_(pyr)),7.20(m, 4, H_(aryl)), 7.00(t, 2, H_(aryl)), 6.67(d, 2, H_(aryl)),2.32(s, 6, N═C--CH₃), 2.10(s, 6, CH₃ aryl).

EXAMPLE 2 Preparation of 2,6-bis[1-(2-ethylphenylimino)ethyl]pyridine,(VIII)

One g of 2,6-diacetylpyridine and 3.0 ml of 2-ethylaniline were added toa round-bottom flask with 30 ml of methanol. A stirbar and 5 drops of97% formic acid were added, and the flask was sealed and the solutionwas stirred for 24 hours at 50° C. The flask was then cooled to roomtemperature and placed in a freezer at -30° C. After 1 day, yellowcrystals had formed. The crystals were isolated by filtration andidentified by ¹ H NMR as the desired product (1.25g, 55.2%). ¹ H NMR(CDCl₃): δ 8.38(d, 2, H_(pyr)), 7.86(t, 1, H_(pyr)), 7.20(m, 4,H_(aryl).sub.), 7.07(t, 2, H_(aryl)), 6.65(d, 2, H_(aryl)), 2.49(q, 4,H_(benzyl)), 2.35(s, 6, N--C--CH₃), 1.14(t, 6, CH₂ CH₃).

EXAMPLE 3

Preparation of 2,6-bis[1-(1-isopropylphenylimino)ethyl]pyridine, (IX)

One g of 2,6-diacetylpyridine and 3.0 ml of 2-isopropylaniline wereadded to an Erlenmeyer flask with 20 ml of methylene chloride. A stirbarand 5 drops of 97% formic acid were added, and the flask was sealed andthe solution was stirred for 40 hours. The solvent was then removed invacuo, and the flask was placed in the freezer at -30° C. The resultingviscous oil was washed with cold methanol, and a yellow solid formed andwas isolated by filtration and identified by ¹ H NMR as the desiredproduct (1.63 g, 66.8%). ¹ H NMR (CDCl₃): δ 8.38(d, 2, H_(pyr)), 7.32(d, 2, H_(aryl)), 7.18(t, 2, H_(aryl)), 7.10(t, 2, H_(aryl)), 6.63(d, 2,H_(aryl)), 3.00(sept, 2, CH(CH₃)₂), 2.37(s, 6, N═C--CH₃), 1.18(d, 12,CH(CH₃)₂).

EXAMPLE 4 Preparation of 2,6-bis-[1 -(1-methylphenylimino)ethyl]pyridineIron[II] Chloride Complex, (X)

(VII) (150 mg, 1.05 eq.) and 84 mg of iron[II] chloride tetrahydratewere added to a Schlenk flask with a stirbar. The flask was back-filledtwice with argon, then charged with 15 ml of THF. Stirring was begun andcontinued for 18 h under static argon pressure, after which the deepblue solid was isolated by filtration and washed with ether and pentane(182 mg, 92%).

EXAMPLE 5

Preparation of 2,6-bis[1-(1-ethylphenylimino)ethyl]pyridine Iron[II]Chloride Complex (XI)

(VIII) (300 mg, 1.05 eq.) and 154 mg of iron[II] chloride tetrahydratewere added to a Schlenk flask with a stirbar. The flask was back-filledtwice with argon, then charged with 30 ml of THF. Stirring was begun andcontinued for 2 h under static argon pressure, after which the deep bluesolid was isolated by filtration and washed with ether and pentane (352mg, 91.7%).

EXAMPLE 6 Preparation of2,6-bis[1-(1-isopropylphenylimino)ethyl]pyridine Iron[II] ChlorideComplex (XII)

(IX) (200 mg, 1.05 eq.) and 95 mg of iron[II] chloride tetrahydrate wereadded to a Schlenk flask with a stirbar. The flask was back-filled twicewith argon, then charged with 15 ml of THF. Stirring was begun andcontinued for 6 h under static argon pressure, after which the deep bluesolid was isolated by filtration and washed with ether and pentane (160mg, 64.0%).

EXAMPLES 7-23 AND COMPARATIVE EXAMPLE A

In these examples, all pressures are gauge pressures of ethylene.

General procedure for Examples 7, 18 and 19: The iron complex wasweighed out and added to a flame-dried 250 ml Schlenk flask with astirbar. The flask was back-filled at least twice with ethylene, thenthe flask was charged with the 50 ml toluene. While stirring, 1 ml ofmodified methylaluminoxane (Akzo Chemical, ˜7% by weight of aluminum inheptane) was added via syringe, and the reaction was allowed to rununder a constant (atmospheric) pressure of ethylene. The oligomers wereisolated by first adding acetone to the oligomerization to destroy anyremaining activator and then by removing the solvent in vacuo. The "K"values and purity of the olefins produced was determined by gaschromatography. The "K" value was calculated from the ratio of C₁₆ /C₁₄compounds in the product mixture.

General procedure for Examples 8-17, 20-23 and Comparative Example A: A1 L Parr® reactor was heated under vacuum overnight, then back-filledwith argon. The reactor was charged with 150 ml of toluene or hexane,and pressurized to 1.4 MPa with ethylene. The reactor was depressurized,and then the iron complex was added (either as a solid or asolution/suspension) together with 50 ml of toluene to the reactor underpositive argon pressure. Then modified 1 ml modified methyl aluminoxanesolution (as above), was added, and then the reactor was quicklyrepressurized while stirring the reaction. After depressurizing thereactor, the oligomers were isolated in the same manner described above.Gas chromatography was again used to determine the product purity and"K" values.

Details about these examples and their results are found in Table 1.Reaction conditions given are the ethylene pressure used, temperature,reaction (rxn) time, and the composition and amount of the iron complex."Solvent" was toluene for all examples, except Examples 20-22 which weredone in hexane, and Example 23 which was done in 95:5 (v:v)hexane:1-pentene. Table 1 also lists solid product isolated, the amountof olefin isolated after applying vacuum, and the total yield, which isthe total of the solids plus olefin isolated, plus olefin lost duringvacuum treatment, as calculated using K, the Schulz-Flory factor. TheTOF, the moles of ethylene oligomerized per hour per mole of ironcompound, based on the total yield, are also listed, as are thepercentages of α-olefin, based on the total amount of olefin presentafter exposure to vacuum.

                                      TABLE 1                                     __________________________________________________________________________             Iron                                                                    Iron Complex pressure   solids isolated total                                Ex. No. Complex μmole Mpa T(° C.) rxn. time g g g K % alpha                                                    TOF                              __________________________________________________________________________     7  (X)  5.7  0.00                                                                              25  3 h   4.86                                                                            12.01                                                                             18.63                                                                             .81                                                                               84.sup.a                                                                         48,000                              8 (X) 0.13 1.4 35 2 h  1.5 68.1 111.5 .74 >99.sup.a 15.5 ×                                                        10.sup.6                            9 (X) 0.13 2.8 80 2 h  -- 175.0 315.6 .73 >99.sup.a 44.0 ×                                                        10.sup.6                           10 (X) 0.13 4.1 90 30 min. -- 114.9 204.9 .70 >99.sup.a 114.2 ×                                                    10.sup.6                           11 (X) 0.13 2.8 90 30 min. -- 74.6 136.1 .70 >99.sup.a 75.8 ×                                                      10.sup.6                           12 (X) 0.13 1.4 90 30 min. -- 36.3 68.4 .70 >99.sup.a 38.1 ×                                                       10.sup.6                           13 (X) 0.10 1.4 60 30 min. -- 20.0 36.3 .73 >99.sup.a 25.3 ×                                                       10.sup.6                           14 (X) 0.09 2.8 60 30 min. -- 53.27 94.9 .73 >99.sup.a 72.1 ×                                                      10.sup.6                           15 (X) 0.09 4.1 90 30 min. -- 133.4 245.3 .70 >99.sup.a 186.4 ×                                                    10.sup.6                           16 (XI) 0.13 1.4 60 30 min. 14.1  10.7 31.3 .79 >99  17.1 ×                                                        10.sup.6                           17 (XI) 0.11 2.8 60 30 min. 18.0  9.4 31.1 .79 >99  19.7 ×                                                         10.sup.6                           18 (XI) 2.2 0.00 25 1 h  2.7 2.4 5.0 .81 >98.sup.a 81,000                     19 (XII) 2.1 0.00 25 1 h  3.2 .94 4.12 .87 >99  81,000                        20 (XI) 0.036 mg 1.4 50 30 min. -- 17.6 24.2 0.82 >99  24.1 ×                                                      10.sup.6                           21 (XI) 0.027 mg 2.8 50 30 min. -- 17.6 22.4 0.82 >99  29.8 ×                                                      10.sup.6                           22 (XI) 0.025 mg 4.1 50 30 min. -- 16.4 20.8 0.82 >99  29.5 ×                                                      10.sup.6                           23 (X) 0.014 mg 2.8 50 30 min. -- 10.7 17.2 0.74 >99  39.9 ×                                                       10.sup.6                           A (XIII) 2.0 1.4 30 30 min. -- --  <1.0 g --   77.2 --                      __________________________________________________________________________     .sup.a Product mixture contained up to 5 mole percent of branched olefins

What is claimed is:
 1. A process for the production of α-olefins,comprising, contacting, at a temperature of about -100° C. to about+300° C., a compound of the formula ##STR15## with ethylene and: (a) afirst compound W, which is a neutral Lewis acid capable of abstractingX⁻ an alkyl group or a hydride group from Fe to form WX⁻, (WR²⁰)⁻ or WH⁻and which is also capable of transferring an alkyl group or a hydride toFe, provided that WX⁻ is a weakly coordinating anion; or(b) acombination of second compound which is capable of transferring an alkylor hydride group to Fe and a third compound which is a neutral Lewisacid which is capable of abstracting X⁻, a hydride or an alkyl groupfrom Fe to form a weakly coordinating anion; wherein:each X is an anion;n is 1, 2 or 3 so that the total number of negative charges on saidanion or anions is equal to the oxidation state of an Fe atom present in(I); R¹, R² and R³ are each independently hydrogen, hydrocarbyl,substituted hydrocarbyl, or an inert functional group; R⁴ and R⁵ areeach independently hydrogen, hydrocarbyl, an inert functional group orsubstituted hydrocarbyl; R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are eachindependently hydrogen, hydrocarbyl, an inert functional group orsubstituted hydrocarbyl; R⁸ is a primary carbon group, a secondarycarbon group or a tertiary carbon group; and R²⁰ is alkyl; and providedthat:when R⁸ is a primary carbon group none, one or two of R¹², R¹³ andR¹⁷ are primary carbon groups, and the remainder of R¹², R¹³ and R¹⁷ arehydrogen; when R⁸ is a secondary carbon group, none or one of R¹², R¹³and R¹⁷ is a primary carbon group or a secondary carbon group and theremainder of R¹², R¹³, and R¹⁷ are hydrogen; when R⁸ is a tertiarycarbon group all of R¹², R¹³ and R¹⁴ are hydrogen; and any two of R⁸,R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶ and R¹⁷ vicinal to one another,taken together may form a ring.
 2. The process as recited in claim 1wherein:R⁴ and R⁵ are methyl or hydrogen; R¹, R², and R³ are allhydrogen; R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen; andR⁸ and R¹⁷ are each independently methyl, ethyl, propyl or isopropyl. 3.The process as recited in claim 1 wherein:R⁴ and R⁵ are methyl orhydrogen; R¹² and R¹³ are hydrogen; and R⁸ and R¹⁷ are eachindependently methyl, ethyl, propyl or isopropyl.
 4. The process asrecited in claim 1 wherein:R⁴ and R⁵ are methyl or hydrogen; R¹² and R¹³are hydrogen; and R⁸ and R¹⁷ are both methyl.
 5. The process as recitedin claim 2 wherein R⁸ and R¹⁷ are both methyl or ethyl.
 6. The processas recited in claim 2 wherein:R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹²,R¹³, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen, R⁸ and R¹⁷ are both methyl; orR⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are allhydrogen, R⁸ and R¹⁷ are both ethyl; or R⁴ and R⁵ are methyl, R⁹, R¹⁰,R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen, R⁸ and R¹⁷ are bothisopropyl; or R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ andR¹⁶ are all hydrogen, R⁸ and R¹⁷ are both n-propyl; or R⁴ and R⁵ aremethyl, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen, R⁸and R⁹ are both chloro; or R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹², R¹³,R¹⁴, R¹⁵ and R¹⁶ are all hydrogen, R⁸ and R¹⁷ are both trifluoromethyl.7. The process as recited in claim 1 wherein said temperature is about50° C. to about 150° C.
 8. The process as recited in claim 1 wherein anethylene pressure is about 500 kPa to about 15 MPa.
 9. The process asrecited in claim 1 wherein a factor K is about 0.7 to about 0.8.
 10. Theprocess as recited in claim 1 wherein W is an alkyl aluminum compound.11. The process as recited in claim 10 wherein said alkyl aluminumcompound is an alkyl aluminoxane.
 12. The process as recited in claim 1wherein:if R⁸ is a primary carbon group, R¹³ is a primary carbon groupand R¹² and R¹⁷ are hydrogen; or if R⁸ is a secondary carbon group, R¹³is a primary or secondary carbon group, and R¹² and R¹⁷ are hydrogen.13. A process for the production of α-olefins, comprising contacting, ata temperature of about -100° C. to about +300° C., a Fe[II] or Fe[III]complex of a tridentate ligand of the formula ##STR16## with ethylene,wherein: R¹, R² and R³ are each independently hydrogen, hydrocarbyl,substituted hydrocarbyl, or an inert functional group;R⁴ and R⁵ are eachindependently hydrogen, hydrocarbyl, an inert functional group orsubstituted hydrocarbyl; R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are eachindependently hydrogen, hydrocarbyl, an inert functional group orsubstituted hydrocarbyl; R⁸ is a primary carbon group, a secondarycarbon group or a tertiary carbon group; and provided that:when R⁸ is aprimary carbon group none, one or two of R¹², R¹³ and R¹⁷ are primarycarbon groups, and the remainder of R¹², R¹³ and R¹⁷ are hydrogen; whenR⁸ is a secondary carbon group, none or one of R¹², R¹³ and R¹⁷ is aprimary carbon group or a secondary carbon group and the remainder ofR¹², R¹³, and R¹⁷ are hydrogen; when R⁸ is a tertiary carbon group allof R¹², R¹³ and R¹⁴ are hydrogen; any two of R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³,R¹⁴, R¹⁵, R¹⁶ and R¹⁷ vicinal to one another, taken together may form aring; an Fe[II] or Fe[III] atom also has bonded to it an emptycoordination site or a ligand that may be displaced by said ethylene,and a ligand that may add to said ethylene.
 14. The process as recitedin claim 13 wherein:R⁴ and R⁵ are methyl or hydrogen; R¹, R², and R³ areall hydrogen; R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen;and R⁸ and R¹⁷ are each independently methyl, ethyl, propyl orisopropyl.
 15. The process as recited in claim 13 wherein:R⁴ and R⁵ aremethyl or hydrogen; and R⁸ and R¹⁷ are each independently methyl, ethyl,propyl or isopropyl.
 16. The process as recifted in claim 13 wherein:R⁴and R⁵ are methyl or hydrogen; and R⁸ and R¹⁷ are both methyl or ethyl.17. The process as recited in claim 13 wherein R⁸ and R¹⁷ are bothmethyl or ethyl.
 18. The process as recited in claim 13 wherein:R⁴ andR⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are allhydrogen, R⁸ and R¹⁷ are both methyl; or R⁴ and R⁵ are methyl, R⁹, R¹⁰,R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen, R⁸ and R¹⁷ are bothethyl; or R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶are all hydrogen, R⁸ and R¹⁷ are both isopropyl; or R⁴ and R⁵ aremethyl, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen, R⁸and R¹⁷ are both n-propyl; or R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹²,R¹³, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen, R⁸ and R¹⁷ are both chloro; orR⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are allhydrogen, R⁸ and R¹⁷ are both trifluoromethyl.
 19. The process asrecited in claim 13 wherein said temperature is about -50 C. to about100° C.
 20. The process as recited in claim 13 wherein an ethylenepressure is about 500 kPa to about 15 MPa.
 21. The process as recited inclaim 13 wherein a factor K is about 0.7 to about 0.8.
 22. The processas recited in claim 13 wherein:if R⁸ is a primary carbon group, R¹³ is aprimary carbon group and R¹² and R¹⁷ are hydrogen; or if R⁸ is asecondary carbon group, R¹³ is a primary or secondary carbon group, andR¹² and R¹³ are hydrogen.
 23. A process for the production of α-olefins,comprising, contacting, at a temperature of about -100° C. to about+300° C., ethylene and a compound of the formula ##STR17## wherein: R¹,R² and R³ are each independently hydrogen, hydrocarbyl, substitutedhydrocarbyl, or an inert functional group;R⁴ and R⁵ are eachindependently hydrogen, hydrocarbyl, an inert functional group orsubstituted hydrocarbyl, R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵ and R¹⁶ are eachindependently hydrogen, hydrocarbyl, an inert functional group orsubstituted hydrocarbyl; R⁸ is a primary carbon group, a secondarycarbon group or a tertiary carbon group; T¹ is hydride or alkyl or anyother anionic ligand into which ethylene can insert; Y is a vacantcoordination site, or a neutral ligand capable of being displaced byethylene; Q is a relatively non-coordinating anion; and P is a divalent(poly)ethylene group of the formula --(CH₂ CH₂)_(x) -- wherein x is aninteger of 1 or more; and provided that:when R⁸ is a primary carbongroup none, one or two of R¹², R¹³ and R¹⁷ are primary carbon groups,and the remainder of R¹², R¹³ and R¹⁷ are hydrogen; when R⁸ is asecondary carbon group, none or one of R¹², R¹³ and R¹⁷ is a primarycarbon group or a secondary carbon group and the remainder of R¹², R¹³,and R¹⁷ are hydrogen; when R⁸ is a tertiary carbon group all of R¹², R¹³and R¹⁴ are hydrogen; and any two of R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴,R¹⁵, R¹⁶ and R¹⁷ vicinal to one another, taken together may form a ring.24. The process as recited in claim 23 wherein:R⁴ and R⁵ are methyl orhydrogen; R¹, R², and R³ are all hydrogen; R⁹, P¹⁰, R¹¹, R¹², R¹³, R¹⁴,R¹⁵ and R¹⁶ are all hydrogen; and R⁸ and R¹⁷ are each independentlymethyl, ethyl, propyl or isopropyl.
 25. The process as recited in claim23 wherein:R⁴ and R⁵ are methyl or hydrogen; and R⁸ and R¹⁷ are eachindependently methyl, ethyl, propyl or isopropyl.
 26. The process asrecited in claim 23 wherein:R⁴ and R⁵ are methyl or hydrogen; and R⁸ andR¹⁷ are both methyl or ethyl.
 27. The process as recited in claim 23wherein R⁸ and R¹⁷ are both methyl or ethyl.
 28. The process as recitedin claim 23 wherein:R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴,R¹⁵ and R¹⁶ are all hydrogen, R⁸ and R¹⁷ are both methyl; or R⁴ and R⁵are methyl, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen,R⁸ and R¹⁷ are both ethyl; or R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹²,R¹³, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen, R⁸ and R¹⁷ are both isopropyl;or R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ areall hydrogen, R⁸ and R¹⁷ are both n-propyl; or R⁴ and R⁵ are methyl, R⁹,R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are all hydrogen, R⁸ and R¹⁷ areboth chloro; or R⁴ and R⁵ are methyl, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵and R¹⁶ are all hydrogen, R⁸ and R¹⁷ are both trifluoromethyl.
 29. Theprocess as recited in claim 23 wherein said temperature is about -50° C.to about 100° C.
 30. The process as recited in claim 23 wherein anethylene pressure is about 500 kPa to about 15 MPa.
 31. The process asrecited in claim 23 wherein a factor K is about 0.7 to about 0.8. 32.The process as recited in claim 23 wherein said compound is (IV). 33.The process as recited in claim 23 wherein said compound (V).
 34. Theprocess as recited in claim 23 wherein said compound is (VI).
 35. Theprocess as recited in claim 23 wherein:if R⁸ is a primary carbon group,R¹³ is a primary carbon group and R¹² and R¹⁷ are hydrogen; or if R⁸ isa secondary carbon group, R¹³ is a primary or secondary carbon group,and R¹² and R¹⁷ are hydrogen.
 36. The process as recited in claim 1wherein said compound is or becomes part of a heterogeneous catalyst ona solid support.
 37. The process as recited in claim 36 carried out inthe gas phase or liquid phase.
 38. The process as recited in claim 13wherein said complex is or becomes part of a heterogeneous catalyst on asolid support.
 39. The process as recited in claim 28 carried out in thegas or liquid phase.
 40. The process as recited in claim 23 wherein saidcomplex is or becomes part of a heterogeneous catalyst on a solidsupport.
 41. The process as recited in claim 40 carried out in the gasor liquid phase.